Copiers and printers using the electrophotographic process contain photoconductors to create a latent image which is developed with toner. The toner on the photoconductor then transfers to paper which then travels through a fuser which fixes the toner on the paper. The transfer of toner from the photoconductor to the paper is not 100% efficient. The residual toner on the photoconductor must be removed. The toner is removed by an elastomeric blade, such as urethane rubber, which scrapes the surface of the photoconductor.
The friction between the cleaning blade and the photoconductor wears the surface of the photoconductor. Various lubricating powders have been used to reduce the friction between the photoconductor and the cleaning blade, such as zinc stearate and graphite fluoride applied to the photoconductor surface. These powders are also removed by the cleaning blade and thus have little effect on reducing the wear on the photoconductor surface. Powders can also migrate to other components in the electrophotographic system, such as contact charging rollers, and this can result in print defects.
Liquid dispersions of zinc stearates or graphite fluoride also have been applied to cleaning blades, which provide longer lasting lubrication, as described in U.S. Pat. No. 5,646,718.